It is known in the operation of internal combustion engines to determine the idle mode of operation of a motor vehicle by a separate actuator (LLS). Values result in idle which differ considerably from the usual operating parameters, which values make it logical to control the idle directly by evaluating the idle actual value rotational speed by providing a so-called idle actuator (LLS) which determines and sets the air quantity to be supplied in bypass to the internal combustion engine for this operating state. More specifically, the idle actuator is installed in a bypass of the choke flap and allows the air flow to be controlled in a classic split-range mode, as idle and normal loads differ considerably. Such an idle actuator can be designed, for example, as a two-winding rotary actuator which adjusts an air-bypass flap by appropriately energizing its windings.
It is also known in the operation of internal combustion engines that gasoline vapors escaping from the tank can be caught, primarily for reasons of environmental protection, usually by means of an activated carbon filter. In addition, the activated carbon filter can be cleaned via an associated tank-venting valve into the intake area of the internal combustion engine by means of an appropriately timed control. As a consequence of this cleaning operation, additional fuel is supplied to the engine which was not taken into consideration in the computation of the particular fuel quantity to be supplied. Also, an excess amount of air which was not taken into consideration is supplied. It is therefore also necessary to introduce a so-called mixture adaptation stop during tank venting phases. This is done to prevent in the highly developed fuel-metering measuring systems of today, which partially learn from actual value behavior feedback, erroneous adaptations and falsifications from occurring in the characteristic fields of the adaptive learning systems as a result of the tank venting quantities which can not be detected. More specifically, it is therefore necessary to stop the so-called mixture adaptation during tank venting phases to avoid potential erroneous values being written into the characteristic fields (memory matrices) of the adaptive systems as a result of this additional non-detectable amount of fuel which acts further as an undesirable offset factor.